1. Field of the Invention
The present invention relates to method and apparatus of recording data onto a disk recording medium in zoned-CLV mode while adjusting recording speed and recording condition adequately at every speed change point between zones.
2. Description of the Related Art
In general, a disk device for writing/reading data to/from a disk recording medium equips with a memory that stores an optimal write strategy of each disk manufacturer, which is identified by a disk code, for each recording speed in order to conduct optimal writing onto an inserted writable disk. Thus, when a data record is requested, the disk device detects a disk code of an inserted disk first, selects an optimal write strategy stored in the memory based on the detected disk code and a recording speed set by a user, and applies the selected write strategy to a recording mechanism that conducts the requested data record.
Consequently, in the conventional art, the selected optimal write strategy is applied to data recording onto a program area of the inserted disk as well as test recording for detecting an optimal writing power.
Meantime, data is recorded onto a rotating disk in CLV (Constant Linear Velocity) 101 or CAV (Constant Angular Velocity) manner 102 as shown in FIG. 1. In the CLV manner, rotating speed must be decreased gradually as a recording position goes outward, so that high speed recording can not achieved by the CLV manner. In CAV manner, recording speed is increased as a recording position goes outward, however, it may be too high to record data onto a track at an outer area. To suppress non-recordable high speed, rotating speed is set such that recording speed at an inner area is very low.
For resolving the respective drawbacks of the two recording manners, a zoned-CLV manner has been introduced. In the zoned-CLV manner, a disk is partitioned into several zones, and CLV is applied within individual zones whereas CAV is applied between zones, as depicted in FIG. 2. Therefore, the zoned-CLV inevitably has recording speed transition points (marked ‘a’,‘b’,‘c’ in FIG. 2).
In case that data is to be recorded at maximum recording speed of each zone, if an initial optimal write strategy selected at start up is maintained up to record end, the write strategy is not optimal after recording zone is changed because recording speed has been increased at a changed zone. Consequently, overall recording operation is not conducted optimally.
For ensuring optimal recording up to record end, recording speed at next zone must be maintained as previous even though recording zone is changed. For example, if record is started at 12× speed at the zone ‘a-b’ of FIG. 2, 12× speed 201 is still maintained at next zones ‘b-c’ and ‘c-d’.
However, such a record can not use maximum recording speed allowable at each zone, so that recording time takes relatively long in comparison with maximum-speed recording at each zone.
Meantime, a recording position goes outward along a spiral track while recording is progressed. However, media characteristic such as thickness is different between inner and outer area, so that it is necessary to compensate such a difference to keep a writing power optimal. For compensation, a disk device detects a B-level reflected by a certain writing pulse, e.g., 11T signal at a start-up operation as shown in FIG. 3, and memorizes the detected level as a base one. Afterwards, if a detected B-level deviates from the memorized base level as a recording position goes outward during data recording, the disk device adjusts an optimal writing power minutely to compensate the B-level deviation This compensating operation is called a running OPC (Optimal Power Calibration).
By the way, as aforementioned, a recording speed must be changed every zone change in the zoned-CLV recording mode if data is to be recorded at maximum recording speed allowable at each zone. Thus, if recording zone is changed, recording speed becomes different from start speed at which the base B-level is detected. In spite of speed change, if running OPC is progressed on a basis of the initial memorized B-level, a minutely-adjusted writing power can not be optimal.